<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			.normal{
				font-style: normal;
			}
			
			.italic{
				font-style: italic;
			}
			
			.oblique{
				font-style: oblique;
			}
			
			.p1{
				font-size: 40px;
			}
			
			.p2{
				font-size: 30px;
			}
			
			.p3{
				font-size: 14px;
			}
			
			.p4{
				font-size: 2.5em;
			}
			
			.p5{
				font-size: 1.875em;
			}
			
			.p6{
				font-size: 0.875em;
			}
		</style>
	</head>
	<body>
		<!--字体样式-->
		<p class="normal">aaaaa</p>
		<p class="italic">aaaaa</p>
		<p class="oblique">aaaaa</p>
		
		<!--字体大小-->
		<h1 class="p1">aaa</h1>
		<h2 class="p2">aaa</h2>
		<p class="p3">aaa</p>
		
		<!--用em来设置字体大小-->
		<h1 class="p4">aaa</h1>
		<h2 class="p5">111</h2>
		<p class="p6">222</p>
	</body>
</html>